Treatment of water with polynucleate metal hydroxide compounds

ABSTRACT

Polynucleate metal hydroxide anionic compounds and method for their production. The compounds have the formula: 
     
       
         M a N b (OH) c X d Y e Z f .(H 2 O) g   
       
     
     wherein 
     M is a tri- or more valent metal ion; 
     N is a divalent metal ion that forms a soluble salt with anions X, Y or Z; 
     OH represents the level of basicity; 
     X is a monovalent anion; 
     Y is a divalent anion; 
     Z is a trivalent anion; 
     a is 1; 
     b is from 0.15 to 2.0; 
     c is from 0.3 to 5; 
     d is from 0 to 3; 
     e is from 0.1 to 2.25; 
     f is from 0 to 1; and 
     g is greater than 4 where the compound is in the form of an aqueous solution, or from 0 to 20 where the compound is not in the form of an aqueous solution. The compounds are useful for water treatment for removal of suspended solids and for various applications in the paper industry.

This is a divisional of application Ser. No. 08/873,295, filed Jun. 11,1997 now Pat. No. 5,938,970.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a new group of inorganic water-solublepolynucleate compounds containing at least two different metals, atrivalent metal and a divalent metal, where both the trivalent metal andthe divalent metal form soluble salts with an associated divalent anion.

2. Description of Related Art

Aluminum sulfate has been the traditional chemical used in various waterand wastewater treatment and paper processing applications. Theseinclude but are not limited to:

clarification of surface water to remove suspended solids, color andbacteria, making the water safe for human consumption or industrial use;

clarification of municipal and industrial wastewaters to removesuspended solids, BOD, COD, phosphates and oils;

retention of fibers and fillers in the production of paper;

sizing of paper to make it hydrophobic; and

control of pitch in the production of paper.

Aluminum sulfate is generally produced by reacting alumina trihydrate(ATH) —Al₂O₃.(3H₂O)— with sulfuric acid in an acid resistant digester.Bauxite containing gibbsite (Al₂O₃.3H₂O)is also used as a low cost rawmaterial for supply of aluminum sulfate.

Aluminum sulfate is normally supplied as a liquid solution containing48.5% Al₂(SO₄)₃.(14.3 H₂O). It may also be supplied as a dry productwhich is dissolved in water prior to use.

Ferric sulfate and other iron salts have begun to replace aluminumsulfate in many of the water and wastewater treatment applications,especially phosphate removal. Ferric sulfate reacts with suspendedsolids in a manner similar to aluminum sulfate but is generally lessexpensive. It is made by reacting ferric oxide with sulfuric acid; inseveral of the processes presently being used, pressure is needed tocomplete the reaction.

In the 1970's, a new class of inorganic polyelectrolytes started toreplace aluminum sulfate. The first products that showed promise werepoly aluminum sulfates. Processes for the production of poly aluminumsulfates are disclosed in U.S. Pat. Nos. 4,284,611 and 4,536,665 andCanadian Patents Nos. 1,123,306, 1,203,364, 1,203,664, and 1,203,665.

In these patents, poly aluminum sulfate is produced by reacting aluminumsulfate solutions with sodium carbonate or sodium hydroxide to form aninsoluble aluminum hydroxide gel, and soluble sodium sulfate which iswashed out of the gel. The gel is then redispersed in a fresh aluminumsulfate solution and reacted at elevated temperatures. The gelredissolves, basifying the aluminum sulfate making a poly aluminumsulfate (PAS).

These reactions may be summarized as follows:

Al₂(SO₄)₃.(14.3 H₂O)+6NaOH+42H₂O→2Al (OH)₃+6Na⁺+3SO₄ ²⁻+56.3H₂O  (IA)

2Al₂(SO₄)₃.(14.3H₂O)+2Al(OH)₃ +50H₂O→→3Al₂(OH)₂ ⁴⁺+6SO₄ ²⁻+78.6H₂O  (IB)

Poly aluminum sulfate solutions with basicities greater than about 15%made using this procedure have exhibited stability problems. Some of thesolutions would be stable for several months where others were onlystable for days. This stability problem was never resolved and thistechnology never reached full commercialization.

U.S. Pat. No. 4,877,597 describes another process for the production ofpoly aluminum sulfate. This process eliminated the initial step ofproducing an aluminum hydroxide gel by reacting aluminum sulfate withsodium aluminate:

3Al₂(SO₄)₃.(14.3H₂O)+2NaAl(OH)₄ ⁻+83H₂O→4Al₂(OH)₂ ⁴⁺+2Na⁺+9SO₄²⁻+97.3H₂O  (IIA)

This reaction results in the preparation of a 33% basic poly aluminumsulfate, although other basicities can be prepared using this procedure.This very reaction is sensitive to temperature, reaction and mixingconditions, and it is difficult to produce products that are stableabove 33% basic. Basicities in the 20% to 25% range are more stable.

U.S. Pat. No. 3,544,476 discloses a process for formation of a polyaluminum chloro sulfate (PACS). It is prepared by first producing analuminum chloride/aluminum sulfate solution and then basifying thissolution with calcium carbonate or lime. PACS is formed and calciumsulfate precipitates. The insoluble calcium sulfate is removed,generating a clear, stable poly aluminum chloro sulfate solution with abasicity of 50% and an Al₂O₃ concentration of 10%.

18Al₂O₃.(3H₂O)+33H₂SO₄+42HCl+867H₂O→11Al₂(SO₄)₃+14AlCl₃+975H₂O  (IIIA)

27Ca(OH)₂+11Al₂(SO₄)₃+14AlCl₃+975H₂O→18Al₂(OH)₃ ³⁺+42Cl⁻+6SO₄²⁻+(27CaSO₄.2H₂O+86H₂O)↓+835H₂O  (IIIB)

This process produces a stable solution and the resulting product is aneffective coagulant. PACS has proven its effectiveness by replacing alumin several applications.

U.S. Pat. Nos. 3,909,439 and 4,082,685 disclose a process for producingpoly aluminum chloride (PAC). This process involves reacting aluminatryhydrate with hydrochloric acid under high temperature and pressureconditions.

 Al₂O₃.(3H₂O)+3HCl+42H₂O→Al2(OH)₃ ³⁺+3Cl⁻+45H₂O  (IVA)

This process produces a stable product at basicities up to 66% and Al₂O₃concentrations up to 18%. The most common product sold is 50% basic and10% Al₂O₃.

Another poly metal salt that has proven an effective product is aluminumchloro hydrate (ACH). It is prepared by reacting aluminum metal witheither hydrochloric acid or aluminum chloride.

5Al+AlCl₃+62H₂O→3Al₂(OH)₅ ⁺+3Cl⁻+47H₂O+7.5H₂(gas)  (VA)

This process produces a stable product at basicities up to 83% and Al₂O₃concentrations up to 24%. The most common product sold is 70% basic at23% Al₂O₃.

U.S. Pat. Nos. 4,981,675, 5,069,893, and 5,149,400 disclose variousprocesses for producing poly aluminum silica sulfate (PASS). In theseprocesses, aluminum sulfate is reacted with an alkali metal silicate andalkali aluminate in an aqueous solution under high shear mixingconditions. The following reaction is typical:

1.25Al₂(SO₄)₃+0.0062(Na₂O.0.322SiO₂)+0.75Na₂Al₂O₄+3H₂O→4Al(OH)_(1.50)(SO₄)_(0.735)(SiO_(2.311))_(0.05)+0.812Na₂SO₄  (VIA)

Products made using this reaction generally have a basicity of 50% andan Al₂O₃ equivalent concentration of 8.3%, althought products withbasicities ranging from 25% to 66% can be made using this technology.

SUMMARY OF THE INVENTION

It is an object of the invention to provide products which perform equalto or better than aluminum sulfate, PAC, PACS, ferric sulfate, ACH andother inorganic coagulants and flocculants.

It is a further object of the invention to provide products which arerelatively easy to prepare compared to other inorganic coagulants andflocculants, and less expensive.

It is an additional object of the invention to provide products whichcan be prepared in an acid resistant tank with standard mixing, withoutthe use of pressure vessels, special high shear mixing or heat tosustain the reaction.

To achieve these and other objects, the invention provides a basicpolynucleate metal hydroxide anionic (PMOA) compound containing at leasttwo metals where one is tri- or more valent and the other is divalent,and the associated anions comprise at least one divalent anion. Thesecompounds have an average composition of:

M_(a)N_(b)(OH)_(c)X_(d)Y_(e)Z_(f).(H₂O)_(g)

wherein

M is a tri- or more valent metal ion, for example aluminum, iron,chromium or zirconium;

N is a divalent metal ion that forms a soluble salt with anions X, Y orZ, for example magnesium, zinc or copper;

OH represents the level of basicity;

X is a monovalent anion, for example chloride, bromide, acetate ornitrate;

Y is a divalent anion, for example as sulfate, selenate or oxalate;

Z is a trivalent anion, for example phosphate or borate;

a is 1;

b is from 0.15 to 2.0;

c is from 0.3 to 5;

d is from 0 to 3;

e is from 0.1 to 2.25;

f is from 0 to 1;and

g is greater than 4 where the product is an aqueous solution, or from 0to 20 where the product is not an aqueous solution.

Other mono- and divalent metals may be present in this PMOA compound upto 15% of the molarity of the trivalent ion M. These metals may includesodium, potassium, calcium and barium.

The basicity of aqueous forms of the compound generally falls in therange of 15% to 60%. Typical basicities are in the 25% to 45% range.

As used in this specification, basicity is defined as [OH]/(3[M]+2[N]),where M is a trivalent metal and N is a divalent metal. If a +4 valencemetal M1 is used, the basicity formula is [OH]/(4[M1]+3[M2]+2[N]), M2being the trivalent metal. Molar concentrations are used in thisformula.

Also within the scope of this invention is a process for producing thePMOA compound. This process comprises reacting a trivalent metal saltsolution, for example aluminum sulfate, ferric sulfate, aluminumselenate, chromic sulfate or zirconium sulfate, with a divalent metal,metal oxide, metal carbonate, metal hydroxide, metal aluminate or otherdivalent metal alkaline material, for example magnesium metal, magnesiumoxide, magnesium hydroxide, magnesium carbonate, zinc oxide, zinc metalor cupric oxide. In this reaction, the divalent alkaline metal is addedto the tri- or more valent metal salt solution.

Also within the scope of this invention is the use of the PMOA productin a flocculating/coagulating/precipitating treatment for suspended ordissolved solids in an aqueous system, including treatment of wastewater and removal of phosphate and algae from lake water and the use ofthese compounds in the production of paper as retention and drainageaids, for sizing paper and controlling pitch.

DETAILED DESCRIPTION OF THE INVENTION

The PMOA products of the invention are unique compared to other polymetal hydroxide compounds in that they incorporate the basifying(divalent) metal into the final product, there are at least two metalsbuilt into the product and there is little or no precipitate resultingfrom the addition of the basifying metal.

The compounds of the invention are formed by reacting an aqueoussolution of a tri- or greater valent metal with a basic solution orsuspension of a divalent metal.

As the trivalent metal, aluminum is preferred. Other trivalent metals,such as antimony, cerium, chromium, cobalt, indium, iron, lanthanum andrhodium can also be used.

Of the metals of valency greater than-3, zirconium, cobalt and tin aremost often used, but platinum, plutonium and uranium may also bementioned.

As the divalent metal, magnesium is preferred. Other divalent metalswhich may be used include beryllium, cadmium, cobalt, copper, indium,iron, nickel, platinum, tin and zinc.

The tri- or greater valent metal will generally be supplied as asolution with a divalent anion, sulfate, oxalate, and borate being mostcommon. However, sulfite, sulfide, selenate, selenite, silicate,silicofluoride, molybdate, citrate and dichromate salts may also beused.

Monovalent and trivalent anions may also be present, includingphosphate, borate and oxychloride.

The divalent metal is generally added as a suspension of the oxide,hydroxide, carbonate or aluminate.

It is also possible to add either metal in metallic form, allowingoxidation to occur in situ in the reactor.

The concentration of the starting tri- or greater valent metal solutioncan vary within a wide range but is generally fairly concentrated, i.e.just below saturation. The solution is supplied at a temperature of lessthan 150°F. (65.5° C.). The divalent metal oxide suspension is added ina stoichiometric amount over a period of 10 to 60 minutes with stirring.The temperature of the suspension must be high enough to result in areaction with the solution, and it may be necessary to heat thesuspension to over 100° F. (37.8° C.) for this purpose. The temperatureof the mixture will increase by 10 to 40° F. (5.6 to 22.2° C.) duringthe reaction.

In industrial environments, increase of the temperature of either thesolution or the suspension can be accomplished by injecting steam intothe reactor or with a heat exchanger.

The reaction will take 1 to 6 hours to go to completion, at which timethe reaction product should be filtered to remove insolubles, includingany unreacted suspension. Dilution water, needed to adjust the finalproduct to a desired concentration, can be added before or afterfiltration.

The final product is tested to determine specific gravity, metal oxidecontent, basicity and pH.

The proper combination of tri- and divalent metals in the compoundresults in products with excellent stability and end use performance.The following examples are examples of stable products prepared based onthis invention. All proportions are by weight, unless otherwise noted.

EXAMPLE 1

To a 1,500 ml glass beaker, were added 590 parts of poly aluminumchloride (41% basic containing 10.6% Al₂O₃) diluted with 225 parts ofwater to lower % Al₂O₃ to below 8.3%. Next were added 130 parts ofaqueous aluminum sulfate solution (containing 8.3% Al₂O₃). The mixturewas heated to approximately 100° C. for three hours and then cooled to25° C.

To a second 250 ml glass beaker were added 25 parts of magnesium oxide(containing 98.5+% MgO) slurried with 30 parts of water. The magnesiumoxide slurry was then added to the first beaker with stirring over afifteen minute period. This mixture was stirred for another four hoursand then filtered to remove unreacted or otherwise precipitatedmaterials.

A reaction took place according to the following formula:

(Poly MACS 7.1CS—50% Basic)

 6MgO+Al₂(SO₄)₃.14.3H₂O+3Al ₄(OH)₅ ⁷⁺+21Cl⁻+411H₂O→7Al₂(OH)₃³⁺+6MgOH⁺+21Cl⁻+3SO₄ ²⁻+419.3H₂O  (VII)

When preparing this 50% basic solution, the numerical values for thevariables were a=1, b=0.44, c=1.9, d=1.5, e=0.2, f=0 and g>3. Thecomposition of the resulting solution was as follows:

Al₂O₃: 7.32%

MgO: 2.48%

Cl: 7.61%

SO₄: 3.05%

Mg/Al: 0.43 (molar ratio), 0.38 (weight ratio)

Cl/SO₄: 6.90 (molar ratio), 2.49 (weight ratio)

Basicity: 48.7%

EXAMPLE 2

To a 1,500 ml glass beaker, 760 parts of aluminum sulfate (containing8.3% Al₂O₃) were added and diluted with 155 parts water. The mixture wasstirred for thirty minutes. To a second 250 ml glass beaker were added38 parts magnesium oxide (containing 98.5+% MgO), slurred with 47 partsof water. This slurried mixture was then added to the stirred dilutedaluminum sulfate over fifteen minutes. The mixture was continuouslystirred for four hours and then filtered.

A reaction took place according to the following formula:

(Poly MAS—33% Basic)

3MgO+2Al₂(SO₄)₃.14.3H₂O+109H₂O→2Al₂(OH)₂ ⁴⁺+Mg₃(OH)₂ ⁴⁺+6SO₄²⁻+134.6H₂O  (VIII)

In this 33% basic solution, the numerical values were a=1, b=0.75,c=1.5, d=0, e=1.5, f=0 and g>3. The composition of the resultingsolution was as follows:

Al₂O₃: 6.31%

MgO: 3.75%

SO₄: 17.70%

Mg/Al: 0.75 (molar ratio), 0.68 (weight ratio)

Basicity: 34.9%

EXAMPLE 3

To a 1,500 glass beaker, 760 parts of aluminum sulfate (containing 8.3%Al₂O₃) were added and diluted with 110 parts water. The mixture wasstirred for thirty minutes. To a second 250 ml glass beaker were added76 parts cupric oxide (containing 98.5+% CuO), slurried with 92 parts ofwater. This slurried mixture was then added to the stirred dilutedaluminum sulfate over fifteen minutes The mixture was heated to 60° C.,continuously stirred for four hours and then cooled to 25° C. andfiltered.

A reaction took place according to the following formula:

(Poly CAS—33% Basic)

3CuO+2Al₂(SO₄)₃.14.3H₂O+109H₂O→2Al₂(OH)₂ ⁴⁺+Cu₃(OH)₂ ⁴⁺+6SO₄²⁻+134.6H₂O  (IX)

In this 33% basic solution, the numerical values were a=1, b=0.75,c=1.5, d=0, e=1.5, f=0 and g>3. The composition of the resultingsolution was as follows:

Al₂O₃: 6.25%

CuO: 7.52%

SO₄: 17.8%

Cu/Al: 0.75 (molar ratio), 1.8 (weight ratio)

Basicity: 31.6%

EXAMPLE 4

To a 1,500 ml glass beaker, 760 parts of aluminum sulfate (containing8.3% Al₂O₃) were added and diluted with 107 parts water. The mixture wasstirred for thirty minutes. To a second 1 liter glass beaker were added78 parts zinc oxide (containing 95.0+% ZnO), slurried with 95 parts ofwater. This slurried mixture was then added to the stirred dilutedaluminum sulfate over fifteen minutes. The mixture was heated to 50° C.and continuously stirred for four hours and then cooled to 25° C. andfiltered.

A reaction took place according to the following formula:

(Poly ZAS—33% Basic)

3ZnO+2Al₂(SO₄)₃.14.3H₂O+109H₂O→2Al₂(OH)₂ ⁴⁺+Zn₃(OH)₂ ⁴⁺+6SO₄²⁻+134.6H₂O  (X)

In this 33% basic solution, the numerical values were a=1, b=0.75,c=1.5, d=0, e=1.5, f=0 and g>3. The composition of the resultingsolution was as follows:

Al₂O₃: 6.35%

ZnO: 7.72%

SO₄: 17.9%

Zn/Al: 0.75 (molar ratio), 1.94 (weight ratio)

Basicity: 32.4%

EXAMPLE 5

To a 1,500 ml glass beaker was added 300 parts of aluminum chloride(containing 10.6% Al₂O₃) and this was diluted with 235 parts of water tolower % Al₂O₃ to below 8.3%. Then 380 parts of aluminum sulfate(containing 8.3% Al₂O₃) were added and the mixture was stirred for threehours. To a 250 ml beaker were added 38 parts of magnesium oxide(containing 98.5+% MgO), slurried with 47 parts of water. This slurriedmixture was added to the stirred mixture of aluminum chloride, aluminumsulfate and water over fifteen minutes. The final mixture was allowed tostir for four hours and was then filtered. A reaction took placeaccording to the following formula:

(Poly MACS 2.1CS—33% Basic)

3MgO+Al₂(SO₄)₃.14.3H₂O+2AlCl₃+126H₂O→2Al₂(OH)₂ ⁴⁺+Mg₃(OH)₂ ⁴⁺+3SO₄²⁻+6Cl⁻+137.3H₂O  (XI)

In this 33% basic solution, the numerical values were a=1, b=0.75,c=1.5, d=1.5, e=0.75, f=0 and g>3. The resulting composition of thefinal mixture is as follows:

Al₂O₃: 6.33%

MgO: 3.75%

Cl: 6.62%

SO₄: 8.93%

Mg/Al: 0.76 (molar ratio), 0.67 (weight ratio)

Cl/SO₄: 2.00 (molar ratio), 0.74 (weight ratio)

Basicity: 34.2%

EXAMPLE 6

To a 1,500 ml glass beaker were added 355 parts of aluminum chloride(containing 10.6% Al₂O₃), diluted with 372 parts of water to lower %Al₂O₃ to below 8.3%. Then 135 parts of aluminum sulfate (containing 8.3%Al₂O₃) was added and the mixture was heated to 80° C. and stirred forthree hours. While maintaining heat at 80°C., 15 parts of aluminum metal(containing 98.0+% Al) were added over a one hour period and the mixturewas stirred at 80° C. for three hours, or until the solution becameclear. The mixture was then cooled to 25° C.

In a second 250 ml glass beaker, 55 parts of magnesium oxide (containing98.5+% MgO) was slurried with 68 parts of water. This slurried mixturewas then added to the reacted mixture now containing a low basic polyaluminum chlorosulfate. The MgO slurry was added to the stirred reactionmixture over fifteen minutes, and the final mixture was stirred for fourhours and was then filtered.

A reaction took place according to the following formula:

(Poly MACS 7.1CS—50% Basic)

6MgO+Al₂(SO₄)₃.14.3H₂O+7AlCl₃+5Al+472H₂O→7Al₂(OH)₃ ³⁺+6MgOH⁺+21Cl⁻+3SO₄²⁻+7.5H₂(gas)+465.3H₂O  (XII)

In this 50% basic solution, the numerical values were a=1, b=0.43,c=1.93, d=1.5, e=0.21, f=0 and g>3. The resulting composition of thefinal mixture is as follows:

Al₂O₃: 7.71%

MgO: 5.40%

Cl: 7.82%

SO₄: 3.17%

Al/Mg: 0.43 (molar ratio), 0.80 (weight ratio)

Cl/SO₄: 6.70 (molar ratio), 2.46 (weight ratio)

Basicity: 46.4%

EXAMPLE 7

To a 1,500 ml glass beaker, 760 parts of aluminum sulfate (containing8.3% Al₂O₃) were added and diluted with 217 parts water. The mixture wasstirred for thirty minutes. To the mixture were added 23 parts magnesiummetal (containing 97.5+% Mg) over fifteen minutes under heat andstirring. The mixture was heated to 80° C. and continuously stirred forfour hours and then cooled to 25° C. and filtered.

A reaction took place according to the following formula:

(Poly MAS—33% Basic)

3Mg+2Al₂(SO₄)₃.14.3H₂O+188.4H₂O→2Al₂(OH)₂ ⁴⁺+Mg₃(OH)₂ ⁴⁺+6SO₄²⁻+211H₂O+3H₂(gas)  (XIII)

In this 33% basic solution, the numerical values were a=1, b=0.75,c=1.5, d=0, e=1.5, f=0 and g>3. The composition of the resultingsolution was as follows:

Al₂O₃: 6.31%

MgO: 3.72%

SO₄: 17.86%

Al/Mg: 0.75 (molar ratio), 0.69 (weight ratio)

Basicity: 35.2%

PERFORMANCE TESTS 1

Several of the compounds made above and commercially available compoundswere tested on water from Lake Haworth, a major sources of water forJersey City, N.J. The raw water conditions were:

Turbidity: 4.2 NTUs

Temperature: 13°C.

Alkalinity: 65 ppm

Standard Treatment: Alum 44 ppm as is, poly DADMAC (poly dimethyldiallyl ammonium chloride) 0.3 ppm.

Comparative test results are shown below in Table 1.

TABLE 1 INORGANIC ORGANIC FILTERED DOSAGE DOSAGE TURBIDITY INORGANIC AsIs ppm ORGANIC As Is ppm FLOC SIZE NTU Alum 58 1 0.65 Alum 64 3 0.57Alum 33 DADMAC 0.3 Pin Point 1.12 Alum 44 DADMAC 0.3 3 0.83 Alum 50DADMAC 0.3 2 0.42 Poly MACS 15 DADMAC 0.3 Pin Point 1.12 7.1CS Poly MACS20 DADMAC 0.3 1 0.69 7.1CS PACS 13 DADMAC 0.3  Pin Point+ 0.48 PACS 17DADMAC 0.3 2 0.45 Poly MAS 20 DADMAC 0.3 3 0.35 Poly MAS 23 DADMAC 0.3 30.25 Poly MAS 26 DADMAC 0.3 3 0.37 Poly CAS 32 2 0.39 Poly CAS 45 2 0.44

The materials used in the testing are defined as follows:

Alum: Commercially available aqueous aluminum sulfate solution, 8.3%Al₂O₃

Poly MACS 7.1CS: Example 1, Reaction VII

Poly MAS: Example 2, Reaction VIII

Poly CAS: Example 3, Reaction IX

PACS: Commercially available product of reaction IIIA and IIIB, 10%Al₂O₃, 50% basic.

The Poly MAS gave the best results. Samples were also prepared where thepoly DADMAC was pre-blended with the Poly MAS. The performance wassimilar to the results obtained above.

PERFORMANCE TESTS 2

Several of the compounds prepared above and commercially availablecompounds were tested on Lake Hiawatha, New Jersey water. The source isthe Boonton reservoir and the main tributary is the Rockaway River. Thisreservoir is one of the major sources of water for Newark, N.J. The rawwater conditions were:

Turbidity: 2.5 NTUs

Temperature: 7° C.

Alkalinity: 50 ppm

Standard Treatment: Alum 16 ppm and poly DADMAC 3.0 ppm.

Comparative test results are shown below in Table 2.

TABLE 2 INORGANIC ORGANIC FILTERED DOSAGE DOSAGE TURBIDITY INORGANIC AsIs ppm ORGANIC As Is ppm FLOC SIZE NTU Alum 21 DADMAC 3.0 1 0.51 Alum 29DADMAC 3.0 1 0.51 Alum 38 DADMAC 3.0 2 0.40 Poly MACS 12 DADMAC 3.0 10.25 7.1CS Poly MACS 14 DADMAC 3.0  1+ 0.36 7.1CS PACS  6 DADMAC 3.0 10.31 PACS  8 DADMAC 3.0 2 0.2 Poly MAS 10 DADMAC 3.0 1 0.26 Poly MAS 13DADMAC 2.5 1 0.25 Poly MAS 16 DADMAC 2.5 2 0.23 Poly CAS 10 DADMAC 3.0 20.34 Poly CAS 13 DADMAC 3.0 2 0.43

The materials used in the testing are defined as follows:

Alum: Commercially available liquid aluminum sulfate solution, 8.3%Al₂O₃

Poly MACS 7.1CS: Example 1, Reaction VII

Poly MAS: Example 2, Reaction VIII

Poly CAS: Example 3, Reaction IX

PACS: Commercially available product of reaction IIIA and IIIB, 10%Al₂O₃, 50% basic.

The commercial PACS gave the best performance followed by Poly MAS.Since the estimated preparation costs for Poly MAS are about 30% ofPACS, the Poly MAS outperformed both the PACS and alum on a costperformance basis.

PERFORMANCE TESTS 3

Several of the compounds prepared above and commercially availablecompounds were tested on wastewater from a paper mill where 100% of thefurnish is recycled paper. The wastewater has the followingcharacteristics:

Suspended solids: 5,000 mg/l

Temperature: 13° C.

Standard Treatment: Alum 4000 ppm as is and poly DADMAC 200 ppm

Comparative test results are shown below in Table 3.

TABLE 3 INORGANIC ORGANIC FILTERED DOSAGE DOSAGE TURBIDITY INORGANIC AsIs ppm ORGANIC As Is ppm FLOC SIZE NTU Alum 4000  DADMAC 200 4  75 Alum3300  DADMAC 200 7 180 Alum 3100  DADMAC 200 10  300 Poly MACS 400DADMAC 200 7 156 7.1CS Poly MACS 600 DADMAC 200 10  271 7.1CS PACS 300DADMAC 200 7 156 PACS 500 DADMAC 200 6 151 Poly MAS 300 DADMAC 200 10 277 Poly MAS 400 DADMAC 200 6 225 Poly MAS 500 DADMAC 200 5 156 Poly MAS1000  DADMAC 200 2  51 Poly MACS 500 DADMAC 200 10  297 2.1CS

The materials used in the testing are defined as follows:

Alum: Commercially available liquid aluminum sulfate solution, 8.3%Al₂O₃

Poly MACS 7.1CS: Example 1, Reaction VII

Poly MAS: Example 2, Reaction VIII

Poly MACS 2.1CS Example 5, Reaction XI

PACS: Commercially available product of Reaction IIIA and IIIB, 10%Al₂O₃, 50% basic.

Poly MAS gave the best results, significantly outperforming alum andgiving performance results comparable to PACS. The PACS is estimated tocost about 3 times as much as Poly MAS to produce.

In addition to the treatment of water and wastewater to coagulate,flocculate and precipitate suspended solids, the compounds of theinvention may also be use for:

treatment of lake water to control phosphate and algae;

removal of oil from wastewater;

control of pitch in the paper industry;

retention and drainage in the paper industry;

sizing paper.

What is claimed is:
 1. A method for treatment of water for removal ofsuspended solids therefrom, comprising adding to the water an effectiveamount of a polynucleate hydroxide ionic compound of the formula:M_(a)N_(b)(OH)_(c)X_(d)Y_(e)Z_(f).(H₂O)_(g) wherein M is a tri- or morevalent metal ion; N is a divalent metal ion that forms a soluble saltwith anions X, Y or Z; OH represents the level of basicity; X is amonovalent anion; Y is a divalent anion; Z is a trivalent anion; a is 1;b is from 0.44 to 2.0; c is from 0.3 to 5; d is from 0 to 3; e is from0.1 to 2.25 f is from 0 to 1; and g is greater than 4 where the compoundis in the form of an aqueous solution, or from 0 to 20 where thecompound is not in the form of an aqueous solution and wherein the moleratio of N to M is greater than 0.44 and the polynucleate metalhydroxide ionic compound coagulates, flocculates or precipitates thesuspended solids from the water for removal of the coagulated,flocculated or suspended solids.
 2. A method according to claim 1,wherein the water is lake water, and the treatment controls phosphateand algae in the lake water.
 3. A method according to claim 1, whereinthe water is reservoir water, and the treatment clarifies reservoirwater.
 4. A method according to claim 1, wherein the water is wastewater, and the treatment removes wastes from the waste water.
 5. Amethod according to claim 1, wherein the water is river water, and thetreatment removes turbidity from the river water.